The Book of Marriage (Kitab Al-Nikah)
Muslim :: Book 8 : Hadith 3443
'Abd al-Malik b. Abu Bakr b. Abd al-Rahman b. al-Harith b. Hisham reported on the authority of his father from Umm Salama (Allah be pleased with her) that when Allah's Messenger (may peace be upon him) married Umm Salama, he stayed with her for three nights, and said: There is no lack of estimation on the part of your husband for you. If you wish I can stay with you for a week, but in case I stay with you for a week, then I shall have to stay for a week with all my wives.